Category Archives: General/Abdominal

SLOW DOWN: Take Your Time in Diagnosing PCOS in Adolescents

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Polycystic ovarian syndrome (PCOS) is the most common ovulation disorder among adult reproductive-age women. This blog post will discuss the latest recommendations, which state that we should wait about 8 years after menarche to make this diagnosis in adolescents!

PCOS is defined by the Rotterdam Criteria as 2 of the following: irregular menstrual cycles (or absent cycles), hirsutism (clinically as acne or male-patterned hair growth or elevated androgens), and polycystic-appearing ovaries on ultrasound, also known as PCO morphology. In addition, other disorders that may look like PCOS need to be ruled out (thyroid disease, hyperprolactinemia, adrenal disorders). The two main areas where patients or providers have difficulty are how cycle lengths are determined and PCO morphology.

In gynecology and infertility, we see a number of women with irregular menstrual cycles. Irregular menstrual cycles are defined as cycles occurring more frequently than every 21 days or less frequently than every 35 days from the beginning of one cycle to the beginning of the next cycle (cycle day 1 to cycle day 1). Some patients get confused and count from the last day of bleeding to the first day of the next period, which artificially makes the cycle seem short. It is good to keep a menstrual calendar (a regular calendar where each day of bleeding is marked with an “X” and review it over a couple of months). It is easy to count the number of days from the beginning of one menstrual cycle to the beginning of the next when counting from the first “X” of one cycle to the first “X” of the next.

One manner of identifying polycystic ovaries is by the volume: If one or both ovaries has a volume of more than 10 cm3 then that meets the criteria for a polycystic ovary on ultrasound.

The other method of identification is counting and measuring follicles. Counting antral follicles, which are follicles that measure as less than 10 mm in diameter, in a polycystic-appearing ovary can be difficult. First, check to see if there are any cysts in the ovary (any large, space-occupying mass greater than 10 mm). If cysts larger than 10 mm are present, then the antral follicle counts and the ovarian volumes will be distorted. Typically, it is easiest to measure the antral follicles and ovarian volume in the early follicular phase, or cycle days 1–5 (where cycle day 1 is the first day of the menstrual period). In this early part of the menstrual cycle, there should not be a dominant follicle growing yet so the ovary commonly has only small antral follicles at this time in the cycle.

Originally, polycystic-appearing ovaries were described as having antral follicles lined up in the periphery of the ovary or a “pearl necklace” sign. In PCOS, the stroma of the ovary produces the androgens, and patients with PCOS tend to have a greater stromal area. However, the Rotterdam criteria did not use these descriptions in defining a polycystic-appearing ovary. Instead, the Rotterdam criteria state a volume or an antral follicle count when there are no cysts. The antral follicle count was initially described in the Rotterdam criteria as either ovary with more than 12 follicles (2–9 mm).

Unfortunately, with this number, a number of adolescents were being misdiagnosed with PCOS. Why would that be?

There are two reasons: one, when girls have menarche, the hypothalamic pituitary ovary axis is not mature and they will have irregular cycles—sometimes this irregularity lasts a couple of years. So, many adolescents were noted to have met the “irregular cycles” criterion. Second, adolescents have an excellent ovarian reserve. They should have a lot of antral follicles because they have a lot of eggs in the early part of their reproductive years. These ovaries are sometimes referred to as multi-follicular ovaries. This is a normal finding.  

Consequently, the international guideline, which has been adopted by the ESHRE (European Society of Human Reproduction and Embryology) and the ASRM (American Society of Reproductive Medicine) has concluded that the number of follicles needed to meet the PCO-appearing criteria should be 20 or more antral follicles (2–9 mm) in either ovary and others recommend 25 or more antral follicles.

They all accept that an ovary larger than 10 mL would meet the criterion. In addition, they have stated that we should NOT make the diagnosis of PCOS in adolescents within 8 years of their menarche because the reproductive axis is not mature early after menarche. Others have recommended NOT using the ultrasound criteria as an independent marker in diagnosing adolescents.

In other words, adolescents will need to have evidence of hirsutism and anovulation to meet the criteria of PCOS. The general consensus is that we do not want to inappropriately place a label of PCOS on these young women. PCOS has a lot of medical sequelae such as infertility, increased risk for insulin resistance, metabolic syndrome, diabetes, hypertension, and many others that could unnecessarily worry the young women.

Take home message: Be SLOW to diagnose PCOS in Adolescents! 

References:

Teede HJ, Misso ML, Costello MF, Dokras A, Laven J, Moran L, Piltonen T, Norman RJ and International PCOS Network. Recommendations form the international evidence-based guideline for the assessment and management of polycystic ovary syndrome. Hum Reprod 2018; 1–17. Doi:10.1093/humrep/dey256

Al Wattar BH, Fisher M, Bevington L, Talaulikar V, Davies M, Conway G, Yasmin E. Clinical practice guidelines on the diagnosis and management of polycystic ovary syndrome: a systematic review and quality assessment study. J Clin Endocrinol Metab 2021; 106(8):2436–2446.

Dumesic DA, Oberfield SE, Stener-Victorin E, Marshall JC, Laven JS, Legro RS. Scientific statement on the diagnostic criteria, epidemiology and pathophysiology, and molecular genetic of polycystic ovary syndrome. Endocrine Reviews 2015; 36(5):487–525. https://doi.org/10.1210/er.2015-2018

https://www.endocrine.org/advancing-research/scientific-statements/polycystic-ovary-syndrome

Elizabeth E. Puscheck, MD, MS, MBA, FACOG, FAIUM, is a board-certified Reproductive Endocrinologist practicing with InVia Ferility and a tenured Professor at Wayne State University School of Medicine.

Impact of Ultrasound on Medical Imaging: 1967–2021

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In 1967, a weekly feature for medical school seniors was the ‘bullpen’ in the Charity Hospital amphitheater. Students were assigned a patient and given 30 minutes to do a history and physical exam and then present their differential diagnosis and recommendations to an attending. Diagnosis was almost exclusively based on the history and physical examination. Laboratory studies were generally confined to basic electrolytes, a CBC, urinalysis, sputum stains, and a chest x-ray.

This prepared me well for internship and residency on the Osler Medical Service at Johns Hopkins Hospital. Interns were on call 24 hours a day for 6 days a week and usually spent 16 to 18 hours a day attending patients at the bedside.

On Osler, there were no computers and handwritten or typed paper records hung on a chart rack. The wards were not air-conditioned, and yellow curtains separated each of the 28 beds. There were no patient monitors, IV pumps, or respirators, and interns performed all of the basic lab work on their patients. Nursing care was excellent; the house staff and nurses worked as a team caring for the patients. Lack of technology was compensated for by close and direct interaction with the patients and their families, and the practice of medicine was extremely satisfying and filled with empathy and compassion.

The patient was the object of all of our attention. In the late 1960s, imaging was limited and played a relatively minor role in diagnosis and management. Defensive medicine was not a concern.

Following my internal medicine residency at Hopkins, I spent the next 3 years in the immunology branch of the National Cancer Institute in Bethesda. The research centered on the new field of bone marrow transplantation and treatment of graft vs. host disease.1 Whole-body radiation prepared candidates for transplantation and my experience in dealing with near-lethal doses of radiation led me to pursue a career in radiation oncology.

After completing a residency in general and therapeutic radiology in 1975, I joined the staff of the Ochsner Clinic in New Orleans, practicing a combination of radiation therapy and general radiography and fluoroscopy. Imaging was film-based, with studies hung on multipanel viewboxes for interpretation and a hot light for image processing. Cases were dictated directly to a transcriptionist in a cubicle next to the reading room and were typed and signed in real time. The daily workload included 40 to 50 barium studies along with numerous oral cholecystograms, intravenous urograms, and chest and bone radiographs. Specialized imaging consisted of polytomography, penumoencephalography, lymphangiography, and angiography. Evaluation of the aorta, runoff vessels, and carotid vessels was performed by direct puncture. Women’s imaging consisted of xeromammograms, hysterosalpingography, and pelvimetry. Image-guided intervention was nonexistent.

That year, ultrasound was in its early clinical development and I acquired a machine and placed it in the radiation therapy department and began scanning patients from the nearby emergency department. At that time there were no other sectional imaging modalities (CT was not yet available for clinical use.).

A large part of the challenge of ultrasound was learning anatomy in a completely new way. As a result, my groundwork in understanding sectional anatomy came from ultrasound. Ultrasound, unlike CT and MR, permitted imaging not only in standardized axial planes but allowed scan planes in virtually any orientation, requiring a very detailed knowledge of anatomy.

In 1976, upon the retirement of Dr. Seymour Ochsner, I became Chair of the department at Ochsner. This provided me with an opportunity to re-equip the department at a time that the entire field of imaging was undergoing immense change. With ultrasound, new findings were being reported regularly2, and the overall quality of ultrasound images often exceeded those of early body CT scans.

The development of Doppler ultrasound in the late 1970s further expanded the applications of ultrasound, although prior to the introduction of color Doppler, this was mainly of interest to vascular surgeons, and diagnosis was based on waveform analysis rather than imaging.

An important technological development at the end of the 1970s was real-time ultrasound, leading to the rapid development of new applications in obstetrical, abdominal, pediatric, and intraoperative imaging3,4.

Developments in computers in the early 1980s led me to an opportunity to participate in the development of exciting new technologies, including a breakthrough involving ultrasound and providing a method to image Doppler information. Working with a small company in Seattle and a large prototype device, we generated the first images of blood flow in the abdomen and peripheral vessels using color Doppler5,6. Color Doppler, by allowing Doppler information to be shown in an image rather than as a waveform, was important in getting radiologists interested in Doppler. Today, color Doppler is an integral part of the ultrasound examination.

A less successful application of ultrasound in the 1980s was in the evaluation of the breast. Early breast scanners produced quality images by scanning the breast, as the patient lay prone in a water tank. Unfortunately, breast ultrasound was promoted aggressively by many manufacturers and by the mid-1980s was discredited as a useful addition to mammography. By the mid-1990s, however, advances in breast ultrasound demonstrated an important role in the evaluation of breast masses, making ultrasound an indispensable part of breast imaging and leading to the BI-RADS breast imaging and reporting system for ultrasound7–9.

Ultrasound also has had a major impact in providing guidance for minimally invasive diagnostic procedures. Fine-needle biopsy of lesions of the liver, kidney, retroperitoneum, as well as peripheral lymph nodes and the thyroid, have become a standard part of the diagnostic workup.

A radiologist of 50 years ago would not recognize the field if he or she were to return today. In fewer than 50 years, the computer has changed the practice of medicine. More precise and early diagnosis are clear benefits of the technology of the 21st century, but are accompanied by the perils of over utilization prompted by defensive medicine with interests of the physician potentially overshadowing those of the patient.

Although the contribution of these advances has benefited countless patients, many of the rewards of the practice of medicine have been diminished. In looking back at my 50 years of practicing medicine, recalling my final grand rounds at Charity Hospital, I appreciate the diagnostic skills acquired through history and physical examination, as well as the relationship I had with my patients during my clinical years. To me, this represents the real definition of being a physician. In many cases, these simple tools were often as effective, and certainly more satisfying, than today’s tendency to view the patient as the result of an imaging test rather than a person.

Christopher R. B. Merritt, MD, is a Past President (1986–1988) of the American Institute of Ultrasound in Medicine (AIUM) where he led the development of the AIUM/NEMA/FDA Output Display Standard, and served as a founder of the Intersocietal Commission for the Accreditation of Vascular Laboratories (ICAVL).

References

  1. Merritt CB, Mann DL, Rogentine GN Jr. Cytotoxic antibody for epithelial cells in human graft versus host disease. Nature 1971; 232:638.
  2. Merritt CRB. Ultrasound demonstration of portal vein thrombosis. Radiology 1979; 133:425–427.
  3. Merritt CRB, Coulon R, Connolly E. Intraoperative neurosurgical ultrasound: transdural and tranfontanelle applications. Radiology 1983; 148:513–517.
  4. Merritt CRB, Goldsmith JP, Sharp MJ. Sonographic detection of portal venous gas in infants with necrotizing enterocolitis. AJR 1984; 143:1059–1062.
  5. Merritt CRB. Doppler colour flow imaging. Nature 1987; Aug 20; 328:743–744.
  6. Merritt CRB. Doppler color flow imaging. J Clin Ultrasound 1987; 15:591–597.
  7. Mendelson EB, Berg WA, Merritt CRB. Towards a standardized breast ultrasound lexicon, BI-RADS: ultrasound. Semin Roentgenol 2001; 36:217–225.
  8. Taylor KWJ, Merritt C, Piccoli C, et al. Ultrasound as a complement to mammography and breast examination to characterize breast masses. Ultrasound Med Biol 2002; 28:19–26.
  9. Berg WA, Blume JD, Cormack JB, et al. Combined screening with ultrasound and mammography vs mammography alone in women at elevated risk of breast cancer. JAMA 2008; 299(18):2151–2163.

Ultrasound in Annual Medicare Wellness Visits?

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Medicare Part B covers many preventive services, such as screenings, shots or vaccines, and yearly Wellness visits, in which a patient’s heart rate, blood pressure, and temperature are evaluated. But, would it be beneficial to add an ultrasound examination?

A team that performs these Wellness visits in a clinic sought to determine whether adding a screening ultrasound examination to the visits would be beneficial for the patients. Six primary care providers, all with advanced ultrasound training, and one ultrasound examiner began a study to find out.

After screening potential patients for the study, each eligible patient gave their consent to be in the study. Note, because their pool of eligible Medicare patients had the following characteristics, they did not represent the nation-wide average:

  • Were at least 65 years old, but not over 85 years;
  • Tended to live independently in an affluent area;
  • Had relatively healthy lifestyles;
  • Had prior access to healthcare;
  • Did not have a documented CT scan of the abdomen or formal echocardiogram in the previous 2 years; and
  • Did not have greater than stage 1 obesity.

Each of the 108 participants underwent an ultrasound examination of the carotid arteries, the heart, and the abdomen, targeting important abnormalities of elderly patients. The patients were not charged for the ultrasound examination.

After the examination, the ultrasound examiner and the primary care provider reviewed the results, discussed them with the patient, and coordinated any needed follow-up care, including 30 follow-up diagnostic items. The patient then completed a 5-question survey about their experience with the ultrasound examination.

Six months later, after the patient’s next Wellness visit, the primary care provider reviewed the patient’s medical record for any follow-up based on the results of the ultrasound examination and assigned each of the 283 abnormalities detected via ultrasound a “benefit score” ranging from –4 (no short-term or potential long-term benefit but serious negative impact occurred because of subsequent care) to 4 (critical clinical benefit, worth all subsequent care). The primary care provider determined the score based on the Medicare reimbursement value of all care received as a result of the ultrasound examination.

Combining the survey results and the abnormality scores, the primary care provider then determined each patient’s net benefit score.

Of all of the abnormalities found, the majority would not have been detected by a traditional physical examination. And although none of them were considered life-threatening, they were frequently markers of chronic conditions, so the primary care provider considered their discovery to be mild to moderately positive.

In conclusion, the study found abnormalities in 94% of the participants. However, only about half of all of the Wellness patients (not just those who participated in the study) would meet the criteria for a screening ultrasound examination, so the examination could not be added to all Wellness visits. For those who qualified, however, in a setting with primary care providers who are experts in ultrasound, the benefit of the examination was rarely negative and often mild to moderately positive, including identifying some new chronic conditions.

To read more about this study, download the Journal of Ultrasound in Medicine article, “An Ultrasound Screening Exam During Medicare Wellness Visits May Be Beneficial” by Terry K. Rosborough, MD, et al. Members of the American Institute of Ultrasound in Medicine can access it for free. Join today!

Interested in learning more about ultrasound? Check out the following posts from the Scan:

Point-of-Care Ultrasound for Internal Medicine: Don’t Forget the Basics

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As specialists in General Internal Medicine, we are excited to see the benefits of incorporating point-of-care ultrasound (POCUS) when assessing medical patients with complex, multi-system disorders. For example, in a patient with heart failure with reduced ejection fraction and chronic obstructive pulmonary disease (COPD) who presents with dyspnea and is found to have diffuse wheezing on auscultation, a number of possible diagnoses exist. Using basic POCUS techniques, findings of asymmetric B-lines, focal pleural irregularity, cardiac findings that seem unchanged from baseline, and a small, collapsible inferior vena cava, increase our suspicion that an infectious precipitant exacerbating the patient’s COPD is the presumptive diagnosis, rather than a primary cardiac cause.

When applied appropriately, POCUS provides real-time data previously not readily available at the bedside. This data can narrow the differential diagnosis [1] and guide intervention. Such benefits of using POCUS to assess medical patients are increasingly known [2–4].  Although new and advanced applications often predominate in the spotlight, basic applications can add a significant amount of information to assist in the care of our patients [5]. The important role that POCUS can play in evaluating medical patients has recently been recognized by the American College of Physicians and Society of Hospital Medicine [6, 7].

As medical educators, we are equally excited about how POCUS can revolutionize bedside teaching—we have seen this tool provide learners with the opportunity to inspect and then confirm the exact location and height of the jugular vein, see then feel a pulsatile liver secondary to severe tricuspid regurgitation, and percuss then visualize a sonographic Castell’s sign [8]. These “aha” moments when our learners see these maneuvers brought to life are incredibly rewarding. However, the excitement that POCUS brings sometimes needs to be balanced by caution.

Despite POCUS being relatively easy to learn, there are multiple pitfalls. The need to apply minimal criteria when acquiring and interpreting images cannot be understated. Just as important as (if not more important than) correctly identifying a positive finding is the ability to recognize when a scan does not meet minimal criteria. Communicating and teaching these limitations to new POCUS users is of paramount importance. Beyond image acquisition and interpretation, achieving competence in clinical integration requires time, repetitive practice, and feedback. As POCUS educators, we frequently see learners flock to advanced applications, such as advanced hemodynamics and detailed cardiac valvular assessments, without necessarily first mastering the basics. Our experience has been that the yield for many of these advanced applications is not high, but the cognitive load in learning them—especially before mastering the basics—is. 

Our approach to using and teaching POCUS is to ensure that we ourselves maintain an appropriate amount of curiosity and humility. We continue to spend time tweaking image acquisition techniques and increasing our understanding of the appropriate uses and limitations of POCUS. This includes expanding our knowledge of the many reasons for false positives and negatives, ensuring our ability to recognize technically limited studies, and maintaining a commitment to finding, applying, and developing the evidence-base to support the use of POCUS for internal medicine. Balancing the tension between experimenting with advanced applications and mastering basic POCUS is sometimes challenging. The steep learning curve of basic POCUS can fool many into thinking mastery has been achieved when there are additional pitfalls to learn.

While we do not wish to dampen learner enthusiasm for high-level applications, we believe there are ways to build learner enthusiasm around basic POCUS. First, we ensure that learners are challenged with cases where clinical integration is complex and nuanced. Emphasis on patient safety and outcomes can help emphasize the need to master basic applications. Second, as educators, we should model a commitment to lifelong learning. Regularly identifying then closing learning gaps can help avoid the illusion that POCUS mastery has been achieved, when in actuality, even basic POCUS applications need to be continually refined and thoughtfully integrated in each unique clinical scenario. This, in addition to encouraging higher-level learners to take a deep dive into high-level applications to appreciate the challenges of these advanced scans, can help maintain while also balancing the excitement of integrating POCUS into the care of complex medical patients. 

REFERENCES

  1. Buhumaid RE, et al. Integrating point-of-care ultrasound in the ED evaluation of patients presenting with chest pain and shortness of breath. Am J Emerg Med 2019; 37(2):298–303.
  2. Filopei J, et al. Impact of pocket ultrasound use by internal medicine housestaff in the diagnosis of dyspnea. J Hosp Med 2014; 9(9):594–597.
  3. Razi R, et al. Bedside hand-carried ultrasound by internal medicine residents versus traditional clinical assessment for the identification of systolic dysfunction in patients admitted with decompensated heart failure. J Am Soc Echocardiogr 2011; 24(12): 1319–1324.
  4. Mozzini C, et al. Lung ultrasound in internal medicine efficiently drives the management of patients with heart failure and speeds up the discharge time. Intern Emerg Med 2018; 13(1):27–33.
  5. Zanobetti M, et al. Point-of-care ultrasonography for evaluation of acute dyspnea in the ED. Chest 2017; 151(6): 1295–1301.
  6. Soni NJ, et al. Point-of-Care ultrasound for hospitalists: A position statement of the Society of Hospital Medicine. J Hosp Med 2019; 14: E1–E6.
  7. Qaseem A, et al. Appropriate use of point-of-care ultrasonography in patients with acute dyspnea in emergency department or inpatient settings: A clinical guideline from the American College of Physicians [published online ahead of print April 27, 2021]. Ann Intern Med. doi: 10.7326/M20-7844.
  8. Cessford T, et al. Comparing physical examination with sonographic versions of the same examination techniques for splenomegaly. J Ultrasound Med 2018; 37(7): 1621–1629.

Janeve Desy, MD, MEHP, RDMS, and Michael H. Walsh, MD, work in the Department of Medicine at the University of Calgary; Irene W. Y. Ma, MD, PhD, RDMS, RDCS, works in the Department of Medicine and Department of Community Health Sciences at the University of Calgary.

Want to learn more about POCUS for General Internal Medicine? Check out the following resources from the American Institute of Ultrasound in Medicine (AIUM):

Axillary and Neck Adenopathy in the Era of Mass COVID-19 Vaccination

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Can you please raise your arm? A few enlarged and unilateral axillary lymph nodes come into view. The cortex is eccentrically or diffusely thickened, they are enlarged, and they are hypervascular. Spotting an abnormal lymph node is not often the challenge, but knowing what to do with the lymph nodes can certainly be. First, I have a confession to make. I am a breast radiologist by training, and I am also fortunate to work in the body division in our department. This opportunity puts me in a unique position to explore both of the worlds and allows for collaboration and the exchange of knowledge.

Any radiologist who performs or interprets ultrasound exams knows that the patient history is of paramount importance along with available previous imaging exams. For example, a recently diagnosed breast cancer, unilateral cellulitis, and lymphoma all influence the management of axillary adenopathy. Similarly, cervical adenopathy can be seen as a reactive finding with head and neck infection, as well as in the setting of known malignancy like head/neck and thyroid cancers, which are prone to metastasize to neck lymph nodes. Vaccination history is also important when considering unexplained adenopathy, and it becomes particularly important with the introduction of the COVID-19 vaccines, which is a mass vaccination undertaking.

The COVID-19 vaccination is administered in the deltoid muscle. As a result, the reactive locoregional adenopathy in the axilla and cervical region has been observed (1). Axillary and/or cervical adenopathy as unsolicited adverse events for the Pfizer-BioNTech vaccine were reported in up to 0.3% among vaccine recipients (as opposed to 0.1% in the placebo group) (2). This adenopathy had onset about 2 to 4 days after vaccination and lasted an average of about 10 days. In the Moderna trial, 1.1% of the vaccination group versus 0.6% of the placebo group reported axillary and/or cervical adenopathy within 2 to 4 days after vaccination (3). However, the median duration of adenopathy with the Moderna vaccine was reported to be 1 to 2 days. It is important to note that these trials did not pursue the incidence of adenopathy via imaging such as ultrasound or regular physical examinations by a practicing physician after vaccination. Therefore, true incidence of axillary or cervical adenopathy remains unknown and is likely much higher than reported.

A total of 0.02% to 0.04% of otherwise normal screening mammograms present with unilateral adenopathy (4-6). During the early months of 2021, it was surprising to encounter a higher frequency of screening mammograms demonstrating unilateral adenopathy, which subsequently required a screening callback for further evaluation. As word spread in the breast imaging community, the Patient Care and Delivery Committee of the Society of Breast Imaging (SBI) issued a set of management guidelines in January 2021 for axillary adenopathy following the COVID-19 vaccination (7).

The dilemma of unilateral adenopathy extended beyond just screening mammograms. Any exams covering the anatomical regions of the axilla and lower neck started to show enlarged lymph nodes. Some examples of these exams include soft tissue ultrasound in the setting of a palpable mass, screening ultrasound exams for indications such as thyroid cancers, and cross-sectional examinations including MRI shoulder exams, CT Chest, and PET-CT.

Locoregional adenopathy has been encountered in the setting of other vaccines like influenza and shingles. However, unlike other vaccines with documented adenopathy among adults, the COVID-19 vaccine is a mass-scale vaccination program and the incidence of adenopathy is expected to be very high in numbers. Furthermore, the vaccination history is not routinely available in the medical chart, at least in early 2021, presumably due to a lack of automated connection between state health departments and unique health center-based electronic medical records. Therefore, effort should be made to document vaccination history either at the time of scheduling or at the time of imaging. At our Institution, the COVID-19 vaccine history including the timing of dose(s) is now routinely reviewed and documented for all breast exams including mammography (both screening and diagnostic), ultrasound, and MRI exams as well as ultrasound exams evaluating the axillary and/or neck regions.

Cancer screening is an important and challenging responsibility. Early detection is important in order to improve mortality and reduce morbidity. The COVID-19 vaccination campaign continues, and the race to protect as many people as possible is more important than ever. As radiologists, it is imperative to follow the data and carefully evolve in order to appropriately diagnose vaccine-related reactive adenopathy while avoiding the unintentional consequence of missing a cancer diagnosis.

A 64-year-old female patient with a history of adenoid cystic carcinoma of the right tongue with prior multiple recurrences and treatments, now presents with a mass along the left thyroidectomy bed. During the initial CT imaging, left thyroidectomy bed mass was confirmed and enlarged left axillary lymph nodes (a) were also noted (largest measuring 10 mm in short axis). This was followed by the PET-CT exam to identify additional sites of metastatic disease. PET-CT was performed about 2 weeks after the initial CT, and the CT component of PET-CT (b) shows decreased size of left axillary node, now measuring 7 mm in short axis. Axial fused PET-CT image (c) shows FDG-avidity of this lymph node, with SUV measurement of 5.56. Ultrasound image (d) shows a round node with no discernible fatty hilum. It was noted that the patient recently received a COVID-19 vaccine prior to the first CT exam. Since biopsy of the thyroidectomy bed mass showed metastasis, biopsy of left axillary node was also pursued, which revealed no evidence of metastatic disease. The left axillary node enlargement was thought to be secondary to recent COVID-19 vaccination. 

So, where do we go from here now that we know adenopathy has been reported with both the Moderna and Pfizer vaccines? Initial consensus statement from a multidisciplinary panel specifically highlights the benefit of prioritizing COVID vaccination among patients with known cancer history, as the protection offered by the vaccine outweighs the unintended side effect of adenopathy (1).

Here, we would like to discuss possible solutions highlighted by the Society of Breast Imaging (SBI) and multi-institutional cancer imaging specialists, along with solutions based on our anecdotal institutional experience, that might be of benefit when faced with the dilemma of adenopathy in your clinical practice following COVID-vaccination.

  • Collaborate with your colleagues in other divisions and departments. Coordinate and establish a consistent algorithm to assist with the management of unexpected adenopathy in the context of recent COVID-19 vaccination.
  • Document COVID-19 vaccination history. This could consist of three phases: 1) The collected information could possibly include date of vaccine doses, laterality of the arm receiving the vaccine, and the brand of the vaccine) prior to a screening exam, particularly when it involves a head/neck or axillary evaluation. 2) Once set up, this strategy of vaccination documentation could then be expanded to all modalities including cross-sectional imaging exams, either at the time of scheduling or at the time of patient’s intake on the day of the exam. 3) The final phase would consist of documentation across your entire hospital system at the time of scheduling of various appointments or using online secured tools to encourage patients to document the same on a voluntary basis. Inter-connection between different systems already existing on many Electronic Medical Record (EMR) systems would be a powerful tool in this regard. Organized COVID vaccination history in a standard location within the EMR could improve accessibility for all healthcare providers.
  • Consider the timing of a routine screening exam. If the screening exam is non-urgent, consider scheduling the exam at a minimum of 4–6 weeks following the second dose of the COVID vaccine (SBI). However, a longer interval of 6 weeks has also been advised in this setting given preliminary evidence of adenopathy persisting at 4 weeks (1). The patient’s existing risk factors and anxiety should also be considered while pursuing delaying the exam.
  • Keep your patients informed. Discuss the known reports of adenopathy following vaccination. Review short-term follow-up as a reasonable initial option in this situation and when biopsy may be indicated.
  • Know when tissue diagnosis may be indicated. According to SBI, in the absence of any other suspicious mammographic finding or contributing history beyond the vaccine, short-term follow-up in 4–12 weeks following the second vaccine dose can be considered. If axillary adenopathy persists after that period of time, tissue diagnosis is warranted to exclude breast and non-breast malignancy. However, for patients with a newly diagnosed breast cancer, it may be more appropriate to rule out metastasis with a biopsy instead of short-interval imaging follow-up.
  • Identify clearly abnormal lymph nodes. Reactive lymph nodes typically present as diffuse enlargement while maintaining their reniform shape. Fatty hilum is present, although could be thinned out. Ultrasound exams might show tiny hypoechoic (not anechoic) areas, indicative of prominent germinal centers. On PET-CT exams, the standardized uptake values (SUVs) of >7.0 have been reported within the lymph nodes as opposed to the typical scenario of reactive lymph nodes in the neck showing SUVs between 2 and 3. However, heterogeneous distribution of SUVs within lymph nodes, clearly necrotic or cystic areas within lymph nodes across all modalities, calcifications on CT and echogenic foci on ultrasound would indicate clearly abnormal lymph nodes, and tissue sampling in these cases will be indicated irrespective of COVID vaccine administration.  

It is important to keep in mind that new knowledge and data continue to contribute to evolving guidelines and that current recommendations may change as we learn more.

Dr. Noelle Hoven is an Assistant Professor in the breast imaging division and Dr. Anil Chauhan is an Associate Professor in the thoracoabdominal division in the diagnostic radiology department at the University of Minnesota.

References:

  1. Becker AS, Perez-Johnston R, Chikarmane SA, et. al. Multidisciplinary Recommendations Regarding Post-Vaccine Adenopathy and Radiologic Imaging: Radiology Scientific Expert Panel. [published online ahead of print February 24, 2021] Radiology. doi: 10.1148/radiol.2021210436.
  1. Polack FP, Thomas SJ, Kitchin N, et al. Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine. N Engl J Med. 2020; 383(27):2603–2615.
  1. Baden LR, El Sahly HM, Essink B, et al. Efficacy and Safety of the mRNA-1273 SARS-CoV-2 Vaccine. N Engl J Med. 2021; 384(5):403–416.
  1. Patel T, Given-Wilson RM, Thomas V. The clinical importance of axillary lymphadenopathy detected on screening mammography: revisited. Clin Radiol. 2005; 60:64–71.
  1. Lim ET, O’Doherty A, Hill AD, Quinn CM. Pathological axillary lymph nodes detected at mammographic screening. Clin Radiol. 2004; 59:86–91.
  1. Chetlen A, Nicholson B, Patrie JT, Harvey JA. Is screening detected bilateral axillary adenopathy on mammography clinically significant? Breast J. 2012; 18:582–587.
  1. SBI Recommendations for the Management of Axillary Adenopathy in Patients with Recent COVID-19 Vaccination. Society of Breast Imaging Patient Care and Delivery Committee. https://www.sbi-online.org/Portals/0/Position%20Statements/2021/SBI-recommendations-for-managing-axillary-adenopathy-post-COVID-vaccination.pdf

Interested in learning more about ultrasound and COVID-19? Check out the following posts from the Scan:

Access the Portal Venous System Safely

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Transjugular intrahepatic portosystemic shunt (TIPS) placement is a well-studied procedure for patients with variceal bleeding, refractory ascites, and hepatic hydrothorax on optimal medical therapy. Despite its efficacy, TIPS remains one of the more technically challenging procedures, particularly related to safely gaining access into the portal venous system.

A typical TIPS procedure involves internal jugular venous access, hepatic vein catheterization, venography, and wedged CO2 portography, and the most challenging step—retrograde portal vein access prior to tract dilatation and stent placement. When using CO2 portography as a landmark for portal venous access, usually several needle passes are required and each additional needle pass increases the risk of adverse events, such as hepatic artery injury, hemobilia, and damage to surrounding structures (kidney, colon, and lung parenchyma).

There have been multiple ways to mitigate this issue, such as biplanar angiography, percutaneous transhepatic guidewire placement within the portal venous system, and cone-beam CT guidance. These methods have had various successes but may require increased procedure time, increased radiation dose, or alternative access sites (for example when placing a microwire into the portal venous system via the transhepatic route).

In our opinion, the best solution for accessing the portal venous system during the TIPS procedure is using intravascular ultrasound guidance with a side-firing intracardiac echocardiographic tip (ICE). The benefit of having ICE guidance is intuitive: it allows for direct visualization of the portal venous target, proper selection of the closest hepatic vein to the respective portal vein, and needle guidance using real-time ultrasound visualization. Therefore, ICE guidance reduces the number of needle passes, the risk of hitting critical structures, and the length of the procedure. Previously, ICE guidance has proven its worth in managing complicated TIPS cases, such as portal vein thrombosis, distorted anatomy from prior surgery or neoplastic disease, as well as TIPS for Budd-Chiari syndrome (direct IVC to portal venous access in these cases).

There have been a few retrospective investigations comparing fluoroscopic guidance to ICE guidance for the TIPS procedure. In a study by Kao et al., the authors did a retrospective comparison between ICE and fluoroscopic guidance. It is interesting to note that the ICE operators were only 2 and 3 years out of fellowship versus 20+ years of experience in the conventional group. The data showed that ICE catheter guidance significantly decreased the number of needle passes, contrast volume, fluoroscopy time, procedure time, and radiation exposure. More importantly, ICE largely reduced the number of “outliers” —those occasional cases in which 30+ needle passes and a few hours of fluoroscopy times are required. It is likely in clinical practice that exactly these outlier cases drive up complication rates.

In a different study, by Ramaswamy et al., the authors did a propensity-matched retrospective review. The data showed the procedure time and outcomes were not significantly different between ICE and conventional techniques. However, there was a significant reduction in contrast volume and radiation in the ICE guidance group. The major caveat of the study was that the ICE operators were much earlier in their career than the conventional group, with an average experience of 4.2 years versus 11 years. The difference in operator experience probably indicates that ICE has the potential to decrease the procedure time when adjusted for operator experience.

Based on the available retrospective studies and our experience, a few points can be confirmed.

  1. ICE decreases the number of needle passes, radiation exposure (to both the patient and operator), and contrast volume.
  2. ICE most likely decreases the procedure time, accounting for differences in operator experience.
  3. ICE will largely eliminate outlier cases that are more likely associated with complex anatomy/clinical scenario and have a higher potential to cause major complications.

In our experience, ICE catheter guidance makes the procedure safer in tough situations. Of course, ICE adds costs (~ $1,000/probe). The modality has a pretty steep learning curve, and it requires an additional venipuncture. In addition, the (more inexperienced) conventional operator can achieve excellent results in routine and/or complex scenarios without using ICE.

In our view, ICE guidance is most helpful in dealing with complex TIPS cases in which a large number of needle passes are expected and complications are frequent. Furthermore, it offers a back-up option when a conventional TIPS procedure runs into unexpected challenges. Instead of blindly sticking another 20 times, we should become familiar with using the available tool (ICE catheter guidance) in our procedural arsenal to provide a safer experience for our patients, ultimately improving outcome in the end-stage liver disease population.

This is a patient referred for re-attempt TIPS from an outside hospital, where multiple attempts of accessing the portal venous system have failed and, therefore, TIPS procedure in the outside hospital had to be aborted. Image A shows the access needle (skinny arrow) directed from the hepatic vein towards a right portal branch (fat arrow). Image B shows the access needle and Bentson guidewire (skinny arrow) within the same right portal branch (fat arrow), indicating successful cannulation. Image C confirms the guidewire (white circle) advanced into the main portal vein. Image D shows the TIPS stent connecting the right portal vein (arrow) with the hepatic vein with free flow of contrast. Portal access was successful on the second puncture with ICE guidance for this (challenging) re-attempt TIPS procedure.

All comments are welcomed; Sasan Partovi can be reached at partovs@ccf.org.

References:

Ramaswamy RS, Charalel R, Guevara CJ et al. Propensity-matched comparison of transjugular intrahepatic portosystemic shunt placement techniques: Intracardiac echocardiography (ICE) versus fluoroscopic guidance. Clin Imaging. 2019; 57:40–44.

Kao SD, Morshedi MM, Narsinh KH, Kinney TB et al. Intravascular Ultrasound in the Creation of Transhepatic Portosystemic Shunts Reduces Needle Passes, Radiation Dose, and Procedure Time: A Retrospective Study of a Single-Institution Experience. JVIR. 2016; 27:1148–1153.

Sasan Partovi, MD, is a staff physician in interventional radiology at The Cleveland Clinic Main in Cleveland, Ohio. Dr. Partovi’s research interests are focused on innovative endovascular treatment options for end-stage renal disease and end-stage liver disease patients. Dr. Partovi has been elected as secretary of the American Institute for Ultrasound in Medicine’s (AIUM’s) Interventional-Intraoperative Community of Practice.

Xin Li, MD, is a radiology resident at the Hospital of the University of Pennsylvania in Philadelphia, Pennsylvania. Dr. Li attended Case Western Reserve University School of Medicine in Cleveland, Ohio, and is pursuing a career in interventional radiology. He currently serves on the Resident, Fellow, and Student Governing Council of the Society of Interventional Radiology.

Interested in learning more about POCUS? Check out the following posts from the Scan:

Shear Wave Elastography and Diffuse Liver Disease

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Diffuse liver disease is a worldwide problem. The causes are several, with non-alcoholic fatty liver disease (NAFLD), alcoholic liver disease, and viral B or C hepatitis being the most frequent. No matter what the cause is, the chronic inflammation of the liver and the cellular death lead to liver tissue scarring, namely liver fibrosis, that may progress to cirrhosis with its complications.

Staging liver fibrosis is important for the management and prognosis of diffuse liver disease. For decades, liver biopsy has been the reference standard for the staging of liver fibrosis.

Shear wave elastography (SWE) is a method able to assess the tissue stiffness by applying a mechanical stress that induces the generation of shear waves, which then propagates into the tissue with a speed that is proportional to the stiffness of the tissue. The shear waves are generated by a body-surface compression, as in transient elastography (TE), or by the push-pulse of a focused ultrasound beam, as in acoustic radiation force impulse (ARFI) techniques.

The speed of the shear waves is related to the stiffness: they travel faster in stiffer tissue. Using a formula and making some assumptions, it is possible to convert the speed into units of stiffness, ie kilopascals.

A fibrotic tissue is harder (stiffer) than a normal tissue, and an increase of fibrosis is coupled with an increase of the stiffness. Therefore, there is a close positive relationship between fibrosis and stiffness.

TE is an SWE technique performed with the FibroScan system (Echosens). This system has a probe with a tip at the end and a button on the lateral part of it. By pushing the button, the tip compresses the body surface and this deformation propagates into the liver as shear waves. An ultrasound beam tracks the shear wave speed and sends information back to the software of the system. The final reading is in kilopascals. The FibroScan quantifies the stiffness but doesn’t assess the morphology of the liver.

The ARFI techniques are implemented in ultrasound systems that are used for other diagnostic purposes when a patient with diffuse liver disease is evaluated. In fact, using an ultrasound system, it is possible to study the organ’s morphology with B-mode, the hemodynamics with Doppler, and to characterize focal liver lesions with contrast agents. ARFI techniques make use of the energy of the ultrasound beam to generate the shear waves whose speed propagation is assessed in m/s: higher the speed stiffer the tissue.

ARFI techniques include point shear wave elastography (pSWE) and two-dimensional shear wave elastography (2D-SWE). pSWE measures the stiffness in a small and fixed region of interest whereas with 2D-SWE the stiffness is obtained over a large field of view and a color-coded image, from which the stiffness value is gotten, is displayed on the monitor of the ultrasound system. The shear wave speed can be converted into kilopascals; the ultrasound systems generally provide both speed values in m/s and stiffness values in kilopascals.

The stress is made directly into the liver; therefore, the examination can be performed also in patients with ascites.

All the published studies have shown that the ARFI techniques have accuracy similar to or higher than FibroScan for the staging of liver fibrosis. Over the last years, the assessment of liver stiffness with SWE techniques, either TE or ARFI, has increasingly been used as a means to noninvasively staging liver fibrosis. Currently, guidelines have accepted that SWE techniques can safely replace liver biopsy in several clinical scenarios. SWE can safely be used also in children. It is feasible in children of all ages and has many pediatric applications in the setting of chronic liver disease.

Bibliography

  • Barr RG, Wilson SR, Rubens D, Garcia-Tsao G, Ferraioli G. Update to the Society of Radiologists in Ultrasound Liver Elastography Consensus Statement. Radiology 2020; 296:263–74.
  • Ferraioli G, Wong VW, Castera L, Berzigotti A, Sporea I, Dietrich CF, Choi BI, Wilson SR, Kudo M, Barr RG. Liver Ultrasound Elastography: An Update to the WFUMB guidelines and recommendations. U Med Biol 2018; 44:2419–2440.
  • Ferraioli G. Review of liver elastography guidelines. J Ultrasound Med 2019; 38:9–14.
  • Ferraioli G, Barr RG, Dillman JR. Elastography for pediatric chronic liver disease: a review and expert opinion. J Ultrasound Med 2020; doi: 10.1002/jum.15482

Giovanna Ferraioli, MD, FAIUM, is a researcher at Medical School University of Pavia, Italy. She’s the lead author of WFUMB guidelines on liver elastography, co-author of the SRU consensus, and of several international guidelines on elastography.

Interested in learning more? Check out the following posts from the Scan:

Point-of-Care Ultrasound for Pregnant Patients?

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Point-of-care ultrasound, or POCUS, has become fully incorporated into almost every aspect of clinical care over the past 5 years. COVID-19 has further solidified the use of POCUS for the evaluation of dyspnea and cough given its portability. But what about the use of POCUS for a woman during pregnancy?

Ultrasound has been consistently employed to evaluate the fetus in all 3 trimesters. There is another patient, though; the mother! Rising maternal morbidity and mortality secondary to cardiovascular disease requires the obstetrical care provider to employ point-of-care clinical assessment that targets the maternal cardiovascular system.  This is the problem and the solution may be “getting a CLUE” by implementing cardiac limited ultrasound evaluation (CLUE) at the bedside as suggested by Kimura et al.

In contrast to fetal imaging, which utilizes higher frequency transabdominal and transvaginal ultrasound probes, penetration of the chest wall requires a lower frequency probe (2–4 mHz). Ideally, a low frequency probe that is compatible with most commonly used obstetrical equipment would facilitate ease of utilization. The CLUE protocol employs the following views: parasternal long axis view, lung anteroapex view, lung posterolateral base view, subcostal view, and right sub-xyphoid view. These views allow the clinician to evaluate the patient for pathophysiologic findings including the presence of pleural or pericardial effusion; abnormal contractility, chamber enlargement, and valvular dysfunction. Assessment of the size and collapsibility of the inferior vena cava can be a noninvasive marker of right-sided filling pressures to evaluate volume status in an oliguric patient with preeclampsia.

I propose that CLUE be extrapolated from the non-pregnant patient population for applicability in the pregnant patient population. This may be particularly relevant in certain scenarios including: triage of pregnant women with cardiac symptoms in an outpatient or in-patient setting as an adjunct to the physical exam; and labor and delivery units with lack, or limited immediate availability, of formal echocardiography. While anecdotal case experience suggest utility, formal studies designed to compare CLUE in pregnancy to the gold standard of transthoracic echocardiography will confirm the feasibility of CLUE in this unique population. Even though obstetricians are trained to perform obstetrical and gynecologic ultrasound, and are well versed with the existing ultrasound equipment on their units, additional training may be required. In addition to obstetrical care providers, other clinicians, such as emergency room and internal medicine providers, may also perform CLUE to assess the maternal cardiopulmonary system.

Limitations of point-of-care cardiac examination of the heart include both patient characteristics and technique. Large body mass size and enlarged breast tissue common in pregnancy can lead to imaging acquisition challenges. Off-axis imaging technique can lead to false positive or false negative diagnoses. Patient positioning should be optimized and shifted to left lateral tilt to accommodate aortocaval compression.

CLUE demonstrates potential as an innovative diagnostic point-of-care technique that can be adapted to maternal use. Timely future clinical studies that compare CLUE with formal echocardiography during pregnancy will further clarify its feasibility and full utility in the clinical arena as a tool to combat rising maternal morbidity in the new millennium.

  1. Kimura BJ, Shaw DJ, Amundson SA, Phan JN, Blanchard DG, DeMaria AN. Cardiac Limited Ultrasound Examination Techniques to Augment the Bedside Cardiac Physical Examination. J Ultrasound Med. 2015;34:1683–1690.

Carolyn M. Zelop, MD, is a Director of Perinatal Ultrasound and Research at The Valley Hospital, Ridgewood, New Jersey; a Clinical Professor of Ob/ Gyn at NYU School of Medicine; and she is a senior member of the AIUM and the ACOG rep to women’s imaging for ACR.

Interested in learning more about ultrasound and pregnancy? Check out the following posts from the Scan:

The Personal Touch: The importance of human interactions in ultrasound

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As I write this, the novel coronavirus COVID-19 is spreading across the globe, inciting fear and anxiety. Aside from frequent hand-washing and other routine precautions, many leaders, officials, and bloggers are advocating for limiting person-to-person contact. This has resulted in cancelation of many professional society meetings, sporting events, and social gatherings, and has stimulated new conversations regarding working from home and virtual meetings. Although these suggestions have many clear benefits (such as the decreased burden of commuting; limiting the spread of infection), there are additional reports describing the impact loss of face-to-face interactions may have on job satisfaction, workflow efficiency, and quality.Fetzer-David-14-2

The current practice of medicine, more than ever, relies on a team approach. No one individual has the time, knowledge, or experience to tackle all aspects of an individual’s care. No one is an island. Unlike many television shows that highlight a single physician performing everything from brain surgery to infectious disease testing, the reality is that we each rely on countless other members of the healthcare team. That practice of medical imaging, ultrasound, in particular, is no different. Whether we work in a radiology, cardiology or vascular, or obstetrical/gynecology practice, the team, and more importantly the relationship between team members, is paramount to an effective and impactful practice.

As a radiologist in a busy academic center, I rely on and value my personal relationship with my team of 50+ sonographers. These relationships have been facilitated by day-to-day, face-to-face interactions, allowing me to get to know the person behind the ultrasound images. These interactions foster an environment of trust. For my most experienced sonographers, my implicit trust ultimately leads to fast, efficient and precise exam interpretations, while for sonographers I rarely work with, my index of suspicion regarding a finding is naturally heightened, impacting my confidence in my diagnosis and thus affecting my interpretation, and ultimately how my report drives patient care.

The trust goes both ways: a strong relationship also fosters honest communication whereby sonographers can come to me with questions or concerns regarding exam appropriateness, adjustments to imaging protocols, and the relevance of a specific imaging finding. The direct interaction provides an opportunity for sonographers, new and experienced, to be provided immediate direct feedback regarding their study—they can learn from me, and often I from them, making us all that much better at the end of the workday.

In addition to trust, open communication allows for users of ultrasound to take advantage of one of the key differentiating features of ultrasound compared to other modalities: the dynamic, real-time nature of image acquisition. Protocol variations can be discussed on-the-fly. Preliminary findings can be shared with the interpreter, and additional images can be obtained immediately, without having to rely on call-backs, inaccurate reports, and reliance of follow up imaging (often by other modalities). This ultimately enhances patient care and decreases healthcare costs. In our practice, we have the ability to add contrast-enhanced ultrasound for an incidental finding, allowing us to make definitive diagnoses immediately, without having to recommend a CT or MRI—this would not be possible if it were not for a personalized checkout process.

We continue to hear about changes in ultrasound workflow across the country: sonographers and physicians, small groups and large, academic and private practices have all considered or have already implemented changes that minimize the communication between sonographer and study interpreter. This places more responsibility on the sonographer to function independently, and minimizes or even eliminates the opportunities for quality control and education. Sonographer notes and worksheets, and electronic QA systems, are poor substitutes for the often more nuanced human interaction. In my experience, these personal encounters enhance job satisfaction, and the lack of it risks stagnating learning and personal drive. There have been many sonographers that have left local practices to join our medical center specifically to take advantage of the sonographer-radiologist interaction we continue to nurture.

Some elements driving these transformations are difficult to change: growing numbers of patients; increasing reliance on medical imaging; medical group consolidation; etc. Many changes to sonographer workflow have been fueled by a focus on efficiency (decreasing scan time, improving modality turn-around times, etc.). Unfortunately, these changes have been made with little regard to how limiting team member communication impacts examination quality, job satisfaction, and patient outcomes; for those of you in a position to address workflow changes, consider these factors. For sonographers yearning for this relationship, do not be afraid to reach out to your colleagues and supervising physicians—ask questions, be curious, and engage with them. Nearly everyone appreciates a human interaction, and even the toughest personality can be cracked with a smile and some persistence. In the end, it is the human interactions and the open and honest communication that not only make us better healthcare providers but happier and healthier human beings.

 

David Fetzer, MD, is an assistant professor in the Abdominal Imaging Division, as well as is the Medical Director of Ultrasound in the Department of Radiology at the UT Southwestern Medical Center.

 

Interested in reading more about communication? Check out the following posts from the Scan:

Ultrasound at the Zoo

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Zoo medicine is quite the paradox. In one way, zoo veterinarians are specialists in that what we do daily; it is very unique and specialized and there are few licensed veterinarians that are employed as full-time clinicians in zoological parks. On the contrary, zoo veterinarians are also the ultimate general practitioners as our patients include everything from invertebrates to great apes and elephants (and all life forms in-between)… and for this wide variety of patients, we attempt to be their pediatrician, surgeon, dermatologist, cardiologist, radiologist, etc. I am fortunate to be the Senior Staff Veterinarian at the Louisville Zoo in Louisville, Kentucky.

In terms of imaging modalities, most zoo hospitals are equipped with plain radiography (film or digital) and have some ultrasound capabilities. A few of the larger zoos in the country have computed tomography (CT) in their on-site hospitals. In Louisville, when one of our patients requires advanced imaging, we make arrangements with local facilities with CT or MRI capabilities.

For ultrasound imaging, we have a portable Sonosite M-Turbo unit with both a curvilinear, 5-2 MHz transducer for primarily transabdominal imaging, and a linear array, 10-5 MHz transducer for primarily transrectal imaging. In addition, we have several donated large rolling Phillips Sonos units with an assortment of probes for both echocardiography and transabdominal imaging. One remains in the Zoo’s Animal Health Center and others are stored and used in animal areas for pregnancy diagnosis, echocardiograms on awake gorillas (through the mesh barrier), or just training/conditioning animals for awake ultrasound exams.

Zoo animals may present unique challenges when ultrasound imaging transcutaneously. In the case of fish and amphibians, imaging through a water bath (without even touching the patient!) can be very effective and noninvasive. The rough scaly skin of some reptiles makes a warm water bath similarly effective as a conductive medium for imaging snakes and lizards. Birds are not often examined via ultrasound because of the extensive respiratory (air sac) system they possess that interferes with the sound waves. For mammals, different species present different challenges. Many mammal species are thickly furred necessitating clipping of hair to establish good contact between the transducer and the skin. For transabdominal imaging, some species are very gassy (hippos, gorillas), which may complicate diagnostic imaging. Large or dangerous mammals that are examined awake via training need to be conditioned to present the body part of interest (chest, abdomen) at the barrier mesh and trust their trainer/keeper to allow contact with the probe. Often the greatest hurdle is habituating the animal to the ultrasound gel! When performing transabdominal imaging in our pregnant African elephant cow, rather than go through gallons of ultrasound gel smeared on her flank to fill in all the cracks and crevices in her thick skin, we run water from a hose just above wherever the transducer is placed.

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As general practitioners, zoo veterinarians have variable amounts of training in ultrasonography. We strive to do the best we can and are constantly learning, but the high variability in our daily tasks makes becoming an expert in ultrasound very difficult. So “it takes a village,” and we will regularly utilize specialists in our community to assist us in providing the best medical care for our patients. If I have a zebra or related species that requires a reproductive ultrasound exam, we will reach out to a local equine veterinarian that can apply their expertise in horses to a related species. Great apes have a high incidence of heart disease so whenever a gorilla or orangutan is anesthetized for an exam, part of the comprehensive care they receive is an echocardiogram by a human sonographer. Female great apes may get attention from our volunteer gynecologic sonographer as part of a reproductive evaluation. If the ultrasound exam is on a sea lion, wolf, or bear, I may contact a veterinary radiologist or veterinary internist competent in ultrasonography to assist.

In summary, ultrasonography represents a valuable, noninvasive, diagnostic tool for the zoo veterinarian.

Have you ever performed an ultrasound examination at a zoo? What was your experience? Comment below, or, AIUM members, continue the conversation on Connect, the AIUM’s online community. 

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Zoli Gyimesi, DVM, is the Senior Veterinarian at the Louisville Zoo in Louisville, Kentucky.